#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int N = 7;
const int M = 1e9+7;

int n;
string s;


int main()
{
#ifdef LOCAL
    freopen("in.txt", "r", stdin);
    freopen("out.txt", "w", stdout);
#endif
    ios::sync_with_stdio(false), cin.tie(0);
    cin >> n >> s;
    puts(s[n-1] == 'o' ? "Yes" : "No");
    return 0;
}